Shortly after noon, officers arrested the 28-year-old man, who is from Flint Hill, Va., after he attempted to enter City Hall with the hammer and began using profanity in the lobby, police said. Officers there told him to leave and called Central District officers, who arrived at the scene and questioned the man outside, police said. Agency spokesman Anthony Guglielmi said the man then made "several threats against police officers," and was taken to the city's homicide unit for questioning.

"He threatened to shoot the officers," Guglielmi said. When police searched a backpack the man was holding, they found a cleaver inside, Guglielmi said.

No one was injured during the incident. City Hall is located at 100 N. Holliday St.

Officers were taking the man to a nearby hospital for a mental evaluation, Guglielmi said.

Police are withholding the man's name because he has not been charged with a crime.

Sen. Ben Cardin has emerged as a central figure in the debate over the pending nuclear deal with Iran, joining a small group of lawmakers who could decide the future of one of President Barack Obama's most significant foreign policies.

After shooting down the state's request for disaster aid for the second time last week, the Federal Emergency Management Agency said Maryland could recover costs associated with rioting that broke out after the death of Freddie Gray in other ways.